SARS-CoV-2 placentitis - report of two cases and review of the literature.

Covid-19 disease caused by severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2) continues to be a global public health problem. Since the pandemic outbreak in early 2020, a number of cases have been reported in pregnant women whose infection has led to severe complications including preterm birth, miscarriage, intrauterine growth restriction or intrauterine fetal demise. The results of the current studies suggest that the transplacental transmission of infection from mother to fetus is a rare event and that the complications listed above are more likely due to damage of placental tissue. In this article, we describe two cases of SARS-CoV-2 placentitis with special consideration to the morphology and differential dia-gnosis of this newly defined entity.

Vacancies and substitutional defects in multicomponent diboride Ti0.25Zr0.25Hf0.25Ta0.25B2: first-principle study.

We study the hard and electrically conductive multicomponent diboride Ti0.25Zr0.25Hf0.25Ta0.25B2with high thermal stability byab-initiocalculations. We focus on the effect of defects (either vacancies or C atoms, both relevant for numerous experiments including our own) on material characteristics. Different types, concentrations and distributions of defects were investigated, and the configurations leading to the lowest formation energies were identified. We show that the replacement of B by C is more unfavorable than the formation of B vacancies. We show that vacancies prefer to coalesce into a larger planar void, minimizing the number of broken B-B bonds and the volume per atom, while carbon substitutions at boron sites do not prefer coalescence and tend to minimize the number of C-C bonds. We show the effect of vacancies on mechanical and electronic properties, and use the results to explain experimental data.

Neurological toxicity due to antimonial treatment for refractory visceral leishmaniasis.

INTRODUCTION: Although pentavalent antimonials are no longer considered the first-line therapy for visceral leishmaniasis in the developed world, they are still used in certain geographical areas and in refractory cases. These drugs have a great number of adverse effects; however, neurological toxicity has been rarely reported. CASE REPORT: We present a 56-year-old woman who required long-term treatment with antimonial drugs due to refractory visceral leishmaniasis and presented clinically with tremor of extremities, myoclonus, gait disturbances and epileptic seizures. The EEG showed increased beta rhythms and generalized epileptogenic activity. She had a slow but favorable response after the withdrawal of antimonials and the initiation of anticonvulsant therapy. CONCLUSION: Severe but reversible neurological toxicity is a rare adverse effect of prolonged antimonial treatment. More EEG record data are needed to support the suspicion of a possible increase of beta rhythms in this situation.